Pneumatically operated compressing tool



Nov. 29, 1960 H. P. DUPRE EI'AL PNEUMATICALLY OPERATED COMPRESSING TOOL Filed D90. 10, 1954 United States Patent a 2,962,074 Patented Nov. 29, 1960,

PNEUMATICALLY OPERIATED COMPRESSING TOO Filed Dec. 10, 1954, Ser. No. 474,519

7 Claims. c1. 153-1 Our invention relates to a portable, power operated compressing tool, and more particularly to a fluidpowcred tool for use in crimping and indenting operations with an automatic control system for insuring a full and complete indent or crimp.

Previously, portable tools for crimping small size connectors consisted mainly of hand operated mechanical tools requiring the operator to exert sufiicient manual force to produce the indentation. This operation becomes strenuous and tiresome after a number of indentations have been made. For large size indentations, hydraulic tools have been devised to provide the necessary pressure to make the indentation, but these tools have great bulk and therefore are not suitable for use in tight quarters. Pneumatic tools have also been devised; however, these consisted of a stationary jaw, and a movable rocker type jaw which moved about a fulcrum pin. This type of tool requires great bulk on the jaws to prevent the tool from springing excessively and breaking off, which did not allow the tool to be used in confined spaces.

It is therefore the principal object of our invention to provide a small power portable compressing tool which is compact and which can easily be operated without fatigue and which also will produce automatically a full depth of crimp or indent.

Further objects of our invention consist in providing an adjustment to take up for the allowable tolerances in manufacture of the dies used to make the indentations and other parts of the tools, and a locking mechanism for this adjustment; to provide an adjustment for the full cycling control system for the various air pressures at which the tool may be operated; to provide means whereby the jaws may be kept either in an open position or a closed position, depending upon the desire of the user of the tool; to provide a means so that the force inducing the cam and piston to travel upwards, will not jam the piston when manufacturing tolerances allow the cam to tilt.

We accomplish these and other objects and obtain our new results as will be apparent from the device described in the following specification, particularly pointed out in the claims, and illustrated in the accompanying drawing, in which:

Fig. 1 is a side elevation of our tool.

Fig. 2 is a longitudinal cross sectional view of the tool taken along the line 2-2 of Fig. 1.

Fig. 3 is a sectional view of the valve shown in the cylinder-charging position, and taken along the line 3-3 of Fig. 1.

Referring to the drawing, the tool comprises a cylinder body 10, and a head 11 which is clamped to the cylinder and locked in position by cap screws 12 and 13. Cover 11A encloses the head and is clamped to the head by screws 11B and 11C. Within the cylinder is reciprocally mounted a fluid operated piston 14 provided with a spherical groove to house a conventional packing ring 15, and an integrally formed extension 16 substantially square in cross-section, having a lateral cam surface 17, a bearing surface 18 and a clearance surface 19 at the end thereof for a purpose to be described later. The other end of the formed extension 17 has a convex spherical radius 20, or ball shape, which mates into a concave spherical radius seat or groove 20A on the piston 14. Special washer 21 and conventional packing ring 22 form a seal for the mating spherical radii. A longitudinal drilled aperture 23 is provided in the extension in which is secured by pin 24, one end of a return tension spring 25, the other end of the spring being anchored to retaining bolt 26 threaded into the bottom of the cylinder.

At the other end of the head there is provided a nose portion 28 to receive a crimping die 28A mounted there in through a pin 29. Fitting through a hole in the frame 11D secured to the head is plunger 30 which is threaded to receive movable die seat 31. The lower part of the die seat, which is threaded to mate in the plunger, is slotted in four parts and also has a hole drilled along the axis to receive an adjustment locking screw 32 which locks the adjustment made when the tolerancesare taken up. Another crimping die 31A is mounted on the die seat through pin 33.

Within the head of the tool, movable rocker 34 is pivotally mounted at fulcrum pin 35. Provided on the rocker is roller bearing 36 pinned at 37, which rides along the cam surface 17. Rocker return spring 38, which has one end mounted at pin 39, fits through the sides of the rocker and bears against spacer 40. Die opening trigger 41 pivots around pin 42, also has pin 43 fitted into it, which rides in slot 44 which is on the rocker. V I

Roller bearings 45 and 46 are mounted within the body or head of the tool by cross pins 47 and 48, respectively, and contact bearing surface 18 of the piston extension to maintain the piston extension in a proper alignment when fully extended for the crimping operation. The cam surface 17 is designed to give the rocker its greatest movement at the start of the indenting operation and to transmit the greatest force'toward the end of the indenting operation.

The lever handle 49 controlling the power operation of the tool, is pivotally mounted through an car 50 at one end, to the circular base portion of the head of the tool by bolt 12. The lever handle extends substantially the length of the body 10 to the end of the body and is provided with offset portion 51 (Fig. 1) at the free end. A small projection 52 on the lever handle near the extending ear, abuts the circular base portion 53 of the head 11 to limit the outward movement of the lever .handle.

As is illustrated in Fig. 3, the valve unit 54 is located at the lower end of the body 10. Two longitudinally drilled fluid passages 55 and 56 lead to the inside of the body and oifset from the center thereof to avoid interference by the anchoring end of the return spring 25; exhaust passage 55 extends to the atmosphere, while inlet passage 56 extends to the inlet port 57, to which is threadedly attached the flexible air inlet hose 58. The valve cylinder 59 is transversely positioned in the valve unit to intercept the passages 55 and 56 and receive the valve piston 60 having an annular undercut groove 61 which contains conventional packing ring 62 to prevent leakage from passages 56 to 55. Thepiston 60 is spring loaded by return spring 63 to an extended positionto block the inlet passage 56, at which time the exhaust port 55 is open to vent the cylinder around the spring end of the piston. The piston is moved inwardly by the offset portion 51 of the lever handle 49, compressing the return spring 63 and aligning the stem 64 of the valve piston with the passage 56 to permitcharging the cylinder, and simultaneously blocking the exhaust passage 55. At the back end of the valve unit located near the return spring, is an adjusting screw 65 which contains a longitudinally drilled hole 66 for release to the atmosphere of any leaking fluid. At the front end of the valve unit is valve adaptor 67 which is counterbored to receive conventional packing ring 68 to prevent leakage around the stem of the valve piston and is held in place by valve adaptor cap 69, which is threaded into the front end of the valve unit. Angularly drilled hole 70 allows fluid leakage to escape through exhaust passage 55 when the valve position is in the fully extended position.

Supporting aperture 71, shown in Fig. 2, located at the end of the valve unit, permits the unit to be conveniently suspended when not in use.

To crimp a connector, the following procedure is followed: the tool being in a non-actuated position, with the valve extended under spring pressure to exhaust the cylinder and the piston extension retracted within the cylinder, the operator depresses the die opening trigger 41 and pin 43, which is attached to the die opening trigger and is within the slot 44 on the movable rocker, pushes against the rocker and allows connecting spring 72, which is attached to the bottom of plunger 30, the other end being attached around spacer 73, which is part of movable rocker 40, to retract the plunger and die seat containing one crimping die. The die opening trigger is depressed against the action of spring 38, allowing the cam roller 36 to clear the piston extension through the clearance surface 19 at the end of the piston extension to permit the movable rocker to open fully. This allows the crimping dies to open fully through the action of the connecting spring 72. The electrical connector 75 is positioned between the dies and the die opening trigger is released, the movable rocker, through the action of spring 38, pushes against plunger 30 and clamps the connector to the fixed crimping die, permitting the tool to be held in any position without the connector falling out, until the operator is ready for the next step. The conductor is then inserted into the connector and the hand lever is depressed by the operator. It is to be noted that regardless of what position the handle of the tool is grasped by the operator, as may be required by the particular location of the conductor, the hand lever can always be easily actuated. When actuated, the hand lever depresses the valve piston 60 against the spring 63 to align the inlet port with the cylinder through the stem 64 of the valve piston. Fluid pressure admitted to the cylinder forces the piston upward against the action of return spring 23, while roller 36 riding along the cam 17 applies the necessary force to the crimping dies through plunger 30 to properly crimp the connector to the conductor. Roller bearings 45 and 46 prevent any lateral movement of the piston extension.

When the piston extension reaches its fully extended position and passes relief hole 74 in the cylinder, and upon release of the hand lever, the valve piston spring pushes the valve piston to an extended position to block the inlet port, and opens exhaust port in the cylinder, the piston being retracted by the return spring, permitting the movable die and movable rocker to be depressed by the die opening trigger and the indented connector removed.

The full cycling control feature which prevents incomplete crimps if the actuating trigger is not depressed long enough, operates as follows: When actuating trigger 49 is depressed, the valve piston 60 is also depressed against the action of spring 63, opening air passages 56 and 57, and blocking exhaust passage 55. This allows fluid pressure to flow into the cylinder. The fluid pressure produces a force on surface 76 of the valve piston which is greater than the returning force of spring 63. A sealed pressure chamber is thereby produced and actuating trigger 49 can be released without the valve piston 60 returning to its outer or extended position.

Therefore, this compels the piston and cam to travel to its fully extended position, thereby producing a complete and full crimp. Upon reaching its fully extended position, conventional packing ring 15 on piston 14 passes the cycling release hole 74 in the cylinder and relieves the sealed chamber which removes the force on surface 76 on the valve piston 60. Valve piston return spring 63 can now push the valve piston back to its extended position. Through this method, it is impossible to obtain anything less than a full and complete crimp. The full cycling control can be adjusted for various fluid pressures by adjustment screw 65, which adjusts the tension on spring 63.

Adjustment for manufacturing tolerances is obtained as follows: With the crimping dies in position and the actuating trigger depressed so that the cam and piston are in their fully extended position, plunger 30 is rotated until the crimping dies are butting firmly against each other. Upon obtaining firm butting of the crimping dies, the lower crimping die is removed and adjustment screw 32 is then tightened. This looks the threaded prongs on the die seat 31 against the internal threads on plunger 30. The lower crimping die is then replaced with the adjustment for that die firmly locked in place. This type of adjustment allows for wider manufacturing tolerances.

The free floating action of the cam and piston is obtained thusly: The rounded ball-shaped end 20 is located at the bottom of cam or piston extension 16 and mates in the spherical seat or groove 20A in piston 14. This allows the piston extension to rotate slightly in any direction through a small angle. Therefore, if manufacturing tolerances or other factors allow the piston extension to tilt slightly, the piston will not tilt within the cylinder due to the mating spherical ball and spherical groove. The piston therefore cannot jam in the cylinder and prevent the tool from functioning properly. This allows wider manufacturing tolerances to be used. Conventional packing ring 22 prevents leakage around the mating spherical ball and spherical groove.

The compactness of the nose of the tool where the crimping dies are located permits great accessibility into locations which are diflicult to get at. The compact head results from having straight line action of the crimping dies which is obtained by changing rocker motion into straight line motion. Compactness of the tool is obtained by locating the return spring within the piston and piston extension, thus avoiding increased lateral and longitudinal bulk. By laterally positioning the die opening trigger and the actuating lever, the tool is easily operated with one hand. Further, by spring biasing the movable rocker so that the connector can be clamped between the dies, only one hand is needed to operate the tool.

The above paragraphs describe the tool with the crimping dies kept in a normally closed position through the action of spring 38, as shown by position A. If it is desired to keep the dies in a normally open position, this can be accomplished by positioning the free end of the spring in position B on the left side of spacer 40. In this case, it is not necessary to provide die opening trigger 41.

We have thus described our invention, but we desire it understood that it is not confined to the particular form or uses shown and described, the same being merely illustrative and that the invention may be carried out in other ways without departing from the spirit of our invention, and, therefore, we claim broadly the right to employ all equivalent instrumentalities coming within the scope of the claims, and by means of which, objects of our invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these re ults.

We claim:

1. In a tool for compressing an article between a fixed jaw and a movable jaw and having means for propelling said movable jaw to compress said article; said movable jaw including: a plunger having an internally threaded bore; a die seat having an externally threaded extension adjustably threaded into said internally threaded bore of said plunger; said externally threaded extension of said die seat including at least a longitudinal slit therethrough and having an axial bore therethrough; locking means adjustably screw threaded in said axial bore; and means to mount a die to said die seat whereby said die seat may be adjustably positioned with respect to said plunger, and said locking means adjusted to lock said die seat in said adjusted position.

2. A fluid operated tool for compressing an article comprising: a cylindrical body, and a head having a jaw fixedly mounted thereto; a movable jaw mounted in a straight slide for linear movement in said head and movable toward said fixedly mounted jaw to compress said article; said movable jaw including a plunger; a die seat adjustably screw threaded into said plunger; said die seat having an axial bore therethrough, locking means adjustably screw threaded in said axial bore; a piston operable in said cylindrical body; a camming section coupled to said piston; a rocker member pivotally mounted in said head; cam follower means coupled to said rocker and disposed to engage said camming section; means coupling said movable jaw and said rocker to lineally advance said movable jaw toward said fixedly mounted jaw in response to movement of said rocker means.

3. A fluid operated tool in accordance with claim 2, wherein said coupling means includes a rotatably movable joint, adapted to permit rotation of said plunger relative to said rocker member, whereby said coupling means is adapted to cause a relative movement between said movable jaw and said fixedly mounted jaw responsive to movement of said rocker means and independent of movement of said piston and camming section.

4. A fluid operated tool comprising: a cylindrical body; a piston operable in said cylindrical body; a valve for admitting fluid pressure to said cylindrical body to operate said piston; an operating lever movable from a first to a second position for initially opening said valve; means responsive to the fluid pressure admitted by the initial opening of said valve to maintain said valve in its open position; means for releasing the fluid pressure applied to said piston when said movable jaw has been 6 fully closed, independently of the position of said operating lever; and means responsive to the release of said fluid pressure for closing said valve when said operating lever has been returned to its first position.

5. A fluid operated tool in accordance with claim 4, wherein said means for releasing the fluid pressure includes an exhaust outlet in said cylindrical body adapted to be opened by the positioning of said piston in its position of maximum extension.

6. A fluid operated tool comprising: a cylindrical body; a piston extensibly operable in said cylindrical body; a valve for admitting fluid pressure to said cylindrical body to operate said piston; means to operate said valve; said valve including a fluid pressure engaging surface to maintain said valve in a fluid admitting position, once said valve has been opened, until the fluid pressure is exhausted into the atmosphere; and means for exhausting said fluid into the atmosphere responsive to the complete extension of said piston.

7. A fluid operated tool comprising: a cylindrical body; a piston operable in said cylindrical body, a source of fluid pressure; a valve for admitting fluid pressure to said cylindrical body; a spring for forcing the valve into a fluid shut-oflf position, said valve provided with a fluid pressure engaging surface for maintaining said valve in the fluid admitting position against the action of said spring; means for initially opening said valve; and means for limiting the inward position of the valve to control the rate of fluid flow.

References Cited in the file of this patent UNITED STATES PATENTS 750,343 Brockway Jan. 26, 1904 2,100,092 Tear Nov. 23, 1937 2,151,563 Platz Mar. 21, 1939 2,176,008 Hoyt Oct. 10, 1939 2,198,129 Sandford et a1. Apr. 23, 1940 2,310,625 Fischer Feb. 9, 1943 2,313,843 Shafl Mar. 16, 1943 2,344,127 Cherry Mar. 14, 1944 2,467,020 Fischer Apr. 12, 1949 2,604,076 Trevaskis July 22, 1952 2,633,161 Schultz et al. Mar. 31, 1953 2,649,076 Dupre Aug. 18, 1953 2,752,214 Ferris June 26, 1956 2,881,738 Baker Apr. 14, 1959 FOREIGN PATENTS 494,963 Canada Aug. 4, 1953 

